The present invention relates to a storage system for storing a file to be accessed from a client, and more particularly to a storage system and a file management device enabling obtaining of a file from a client without designating detailed information.
When holding electronic data in a storage or the like, there are problems relating to the retention period of the electronic data. As the amount of data increases, the demanded capacity of the storage also increases, requiring higher costs. Therefore, important data is recorded in a high-speed storage with a wide bandwidth, and unimportant data is recorded in a relatively low-speed storage. Such a high-speed storage with the wide bandwidth is expensive, and such a relatively low-speed storage is inexpensive. Further, based on the date when the data is saved (i.e., the archived date), fresh data (data for which not much time has elapsed since being archived) is recorded in the high-speed storage, and less fresh data (data for which a predetermined period has elapsed since being archived) is recorded in the low-speed storage. This type of data management method is called Data Lifecycle Management (DLCM).
As a scheme for saving files with long-term saving of files in Data Lifecycle Management (DLCM) taken into consideration, there is known a WORM (Write Once Read Many) archive that manages modification and deletion of files within the retention period.
For example, there is known a WORM archive, in which a WORM file stored by a WORM archive server is managed by means of a unique identifier, and for each file, an identifier, a file location in the storage, and a file attribute are recorded (refer to EMC Corporation, “EMC Centera”),
Alternatively, there is known a WORM archive, in which a file inside a WORM archive server is managed by the same path name as a path name on a client (e.g., see Network Appliance, “NetApp NearStore”).
The client that reads out the WORM file designates, via a WORM archive client library, either the identifier or a set of the file name and the archived date, whereby the WORM file can be read out.
Furthermore, in the “EMC Centera”, when re-archiving a WORM file that was read out and then modified by the client, the WORM file is archived as a WORM file having a different identifier.